Spray gun



FIG. 1 is an oblique front view showing my new design of a spray gun;

FIG. 2 is an oblique back view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a right side view thereof; and,

FIG. 5 is a top view thereof. 

The ornamental design for a spray gun, as shown and described. 